plotting an equation and finding its max and min

8 次查看（过去 30 天）
tyler Wallis
tyler Wallis 2018-1-28
回答： Aman Kumar 2021-1-5
I would like to plot my function n_sx from 0 to 2*pi and find its max and min over that interval. I know that I can use fplot to plot the function and have done so successfully but I can't find a way to find the max and min using fplot. I've tried plotting my equation using plot but I keep getting errors. Any ideas? thanks
clc;close all
syms z t
E1=15.8;
E2=12.9;
G12=2.7;
v12=0.16;
m=cos(t);
n=sin(t);
y=n_sx==n*m*(m^2*(2+2*v12-E1/G12)+n^2*(-2*v12-2*E1/E2+E1/G12))/(m^4+m^2*n^2*(-2*v12+E1/G12)+n^4*E1/E2)
x=t==linspace(0,2*pi,50);
plot(x,y)
indexmin = find(min(y) == y);
xmin = x(indexmin);
ymin = y(indexmin);
indexmax = find(max(y) == y);
xmax = x(indexmax);
ymax = y(indexmax);

请先登录，再回答此问题。

采纳的回答

Nicolas Schmit
Nicolas Schmit 2018-1-29
E1=15.8;
E2=12.9;
G12=2.7;
v12=0.16;
x=linspace(0,2*pi,50);
t = x;
m=cos(t);
n=sin(t);
y=n.*m.*(m.^2.*(2+2.*v12-E1./G12)+n.^2.*(-2.*v12-2.*E1/E2+E1./G12))./(m.^4+m.^2.*n.^2.*(-2.*v12+E1./G12)+n.^4.*E1./E2);
plot(x,y)
indexmin = find(min(y) == y);
xmin = x(indexmin);
ymin = y(indexmin);
indexmax = find(max(y) == y);
xmax = x(indexmax);
ymax = y(indexmax);

更多回答（1 个）

Aman Kumar
Aman Kumar 2021-1-5
E1=15.8;
E2=12.9;
G12=2.7;
v12=0.16;
x=linspace(0,2*pi,50);
t = x;
m=cos(t);
n=sin(t);
y=n.*m.*(m.^2.*(2+2.*v12-E1./G12)+n.^2.*(-2.*v12-2.*E1/E2+E1./G12))./(m.^4+m.^2.*n.^2.*(-2.*v12+E1./G12)+n.^4.*E1./E2);
plot(x,y)
indexmin = find(min(y) == y);
xmin = x(indexmin);
ymin = y(indexmin);
indexmax = find(max(y) == y);
xmax = x(indexmax);
ymax = y(indexmax);

类别

在 Help Center 和 File Exchange 中查找有关 Symbolic Math Toolbox 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by